In the CATV broadcasting system, which is the system presently and widely in use in the United States and in many other countries, television signals are transmitted by multiple cables from the broadcasting center, which is the program supplier, to subscribers' reception terminals which are installed at the program viewer's site. In this system, a program viewer looks for and selects a desired program out of a large number of programs supplied from the broadcasting center, in general, by successively tuning in the channels one by one at the subscriber's reception terminal. For this reason, the greater number of the program channels, the more complex and troublesome the handling of the tuning operation becomes.
Recently, a multi-screen display has been used which is formed by dividing the screen of the television set cooperating with the reception terminal into a plurality of sub-screens on which the programs of different channels are respectively and simultaneously displayed. Such a multi-screen display has been tried in order to make the tuning operation easy. However, in the conventional system, the image for the multi-screen display is formed by the reception terminal at the subscriber side by means of editing the images of a plurality of television signals. Therefore, the reception terminal is required to use a memory with a large capacity so as to store all the images of the television signals corresponding to the programs involved in the multi-screen display. As a result, in the case where the multi-screen display is employed in the conventional system, the reception terminal suffers the disadvantage of being complex in construction and high in cost, so that it is unsuitable for practical use.
Moreover, in the television system known in the prior art, when forming the above multi-screen display on the television set, no audio signals of the programs are produced on the multi-screen display. Therefore, it is impossible to select a desired program by listening to the audio of the programs in cooperation with the multi-screen display.